Conversion of continuous filaments into staple fiber yarns and like products



0st. 10, I944.

c. H. HAYS ET AL 2,359,847 CONVERSION OF CONTINUOUS FILAMENTS INTO STAPLE FIBER YARN AND LIKE PRODUCTS Filed June 26, 1941 C-H-HAYS W A. DICKIE INVENTORS 9 Patented Oct. 10, 1944 ooNvEnsmN or CONTINUOUS murmurs m'ro STAPLE FIBER YARNS AND mm PRODUCTS Claude Hui-rocks Hays, London, and William Alexander Dickie, Spondon, near Derby, England, assignors to Celanese Corporation of America, a corporation of Delaware Application June 26, 1941, Serial No. 399,868

' In Great Britain October 25, 1940 l 9 Claims.

This invention relates to' the direct conversion of continuous filaments into staple fiber yarns and like products, especially by the application of a breaking tension to a bundle of continuous filaments.

The invention is especially concerned with the production of staple fiber threads of fine character, and especially threads closely simulating fine threads of natural origin, e. g. linen, worsted, and cotton threads and having the characteristic of varying thickness that for many purposes is an attractive feature of natural threads. The invention is not, however, confined to the production of fine threads only, nor to threads having thickness variations only within the range encountered in natural threads, the operations' for carrying out the invention being capable of adjustment to give a range of products varying substantially as regards thickness, and as regards the amounts by which the thicknessv varies.

According to the invention a bundle of continuous filaments is passed through successive sets of drafting rollers, the second set of rollers encountered by the bundle being driven with a peripheral speed substantially in excess of that of the first set so as to exert a draft of at least times, or preferably times or' much higher, e. g. 15, 20, 30, 40, 50 or more times, on the filaments, the speed of the second pairorset of rollers being. however, varied at regular or irregular intervals so as to produce 2. corresponding variation in the draft applied to the bundle of'filaments. The filaments are thus stretched to breaking tension and thereby converted into staple fiber, and at the same time the bundle is considerably reduced in size, and given a variation in thickness simulating, or even accentuating, the variation frequently exhibited by natural fibrous yarns. Filaments having a varying. denier may be employed, the variations either occurring at the same point in the length of the bundle under treatment or, if desired, being somewhat. distributed throughout the length of the bundle, for example, in the latter case the bundle to be treated may be built up of several smaller bundles, the thicker portions of which do not coincide.

It is important to start with aibundle of large size, the bulk being reduced by the large draft applied, which draft is, as indicated by the figures given above, considerably higher than is normally used in single-stag drafting of ordinary textile fibers. In this way, a satisfactory product is obtained in one' operation, counts equivalent to 45 denier being possible in-the single drafting.

Very good results are obtained by using artificia1 filaments of cellulose ester basis that have been stretched so as to have a high strength, e. g.

about 4.5 grams per .denier or upwards, or

upwards, or stretched and saponified so as to be still stronger, e. g. about 6 grams per denier or applicable to the treatment of stretched polyamide filaments.

The invention is, however, applicable to the conversion into staple fiber threads .of artificial filaments of normal character, i. e., of normal strength, e. g. ordinary cellulose acetate or other cellulose ester and ether filaments or viscose or cuprammonium filaments, these materials working very well under the conditions already mentioned of starting with a large bulk and reducing this byvery substantial draft.

. The initial filaments may be lustrous (bright) or delustred, in accordance with the requirements of the finalyarn, especially if the desire is to simulate natural yarns having bright- 4 ness or dullness as-a characteristic. Pigments, which can be incorporated in various propor-. tions, are particularly useful in controlling the degree of dullness.

The bundle may be passed in wet condition through the pairs-of rollers, as for example by being carried into a trough disposed immediately in advance of the first pair of rollers, one or more rods or rollers keeping the bundle below the liquid. Thewetting may be carried out simply by means of water, which may becold, but with advantage is heated to, say, 90-95 C.

It is sometimes found that this wetting facilitates the breaking 'and' fdrafting operation. Possibly some softening of the material of the filaments is obtained and in addition a lubrication 1 of the material that facilitates the sliding re-.

having a. long aliphatic chain, preferably with more than 12 carbon atoms; salts of higher fatty acids, sulphonated oils, e. g. Turkey red oil, and salts of sulphates of higher fatty alcohols. Such additions probably assist the wetting out of the material as well as aiding the lubrication.

The drafting rollers may be similar to those of the wet .line machine used in the spinning of flax. Thus the first pair of rollers encountered may b of brass about 1 /2" in diameter and having about 28 longitudinal corrugations to the inch; the next pair of rollers may be similarly corrugated, the lower roller being of brass about 2% in diameter and the upper one of wood, say, We-4V2" in diameter. The size of the rollers may be varied in accordance with the reach employed. The use of a metal such as brass guards against rusting in the case where the material is treated wet. The rollers are suitably loaded .so that the filaments are firmly gripped by the inter-meshing corrugations. Preferably the greater part of the load should be applied to the first pair of rollers to maintain good control over thebulky bundle during the drafting. The drafted product may be twisted by a fiyer spindle.

The operation may, however, be carried out dry, in which case a somewhat different rollersystem may be used. The first pair of rollers (which may be of steel) are about 1 /2" in diamters with about 8 corrugations or flutes to the inch. Advantageously, however, the rollers may be leather faced. It is also useful to reverse the direction of rotatidnof these rollers so that by carrying the bundle from a traverse bar above the rollers round the back ofthe rear roller, up through the nip, and over the front roller, a greater surface of contact is obtained to retain full control over the bundle. The other rollers are plain, the front one being of steel about 3 /2- 4" in diameter and the rear one of wood about 56" in diameter. Suitable loading is applied as in the case of the'wet operation.

For simulation of a linen thread the reach between the two pairs of rollers may be 1% up wards. This spacing may be fixed or any particular apparatus may be provided with a roller adjustment, so that reaches of say 2 /2", 5" or 10", or intermediately, may be readily obtained.

In the dry operation. a reach of 14" upwards, say 16", 18", or 20",. is very convenient, but lower reaches of say 6", used.

The invention lends itself to the production of a wide range of linen-like threads. Thus for the production of a coarse thread a bundle of 8,000, 1 2,000 or 15,000 denier may be subjected to 6-10- times draftto produce a staple fiber thread of about 800 to 2000 denier, the staple length being; say 2 /2 or 5". A twist of, say 3 or 4 /2 turns per inch may be inserted, for example,

- by ring spinning or flyer spinning the product delivered from the breaking rollers.

A finer thread may be produced by subject ing an initial bundle of 1,000 to 2,000 denier-"to a draft of 6-10 times. In this way a final thread of about 180 denier with T6-8 turns or other number per inch may be formed in the acne Opera- -tion, and, by higher drafting, finer still down to denier.

8'}, 10" or 12" may be wetting liquid soaps orother salts of'compounds The operation may also be carried out on spinning machines of the type used for worsted 'or natural silk with varying reaches of from and then to a second set comprising a leather-,

rubber-, or cork-faced roller spring-loaded on to a steel roller. A draft of 40 or 50 times may be applied. Thus, a 6000-denier bundle may be reduced in one stageto 150 denier. Two-stage operation may, however, be employed. Thus, a BOOO-denierbundle may be first reduced to an intermediate denier yarn or roving, in which say 1 turn' per inch of twist may be inserted, and this may then be reduced to 50-55 denier in a second operation, the final thread being collected by capor flyer-spinning. The two operations have a joint draft of about 120 times.

The starting material may-be wound on long bobbins for free rotation about vertical, inclined,

or horizontal axes in a creel from which the material is guided to the drafting rollers, or in the case of wet treatment, to the trough con-,

taining the wetting liquid. Cheeses may likewise be used. i

If the initial filaments have been produced by a stretching operation considerable variation may be made in the filament denier. Thus, for example, by stretching a cellulose acetate filae ment of 15 denier 10 times and then saponifying the stretched product a final filament denier of one may be obtained. By stretching filaments initially of finer denier and/or applying greater degrees of stretch finer filament deniers, e.-g. 0.4 or less, say 0.1, may be employed. Likewise filament deniers in excess of one may be used if desired, the choice available permitting substantial variation in the final staple fiber product.

Generally, however, higher filament deniers such as 3, 3 4, or 43 draft satisfactorily and yield good yarns, and in such cases non-stretched yarns, bright or dull, may conveniently be used.

The accompanying drawing shows diagrammatically one way of carrying out the invention on a machine of the type used for spinning worsted or natural silk.

A continuous filament bundle I is led from a bobbin 2 braked by a felt washer 3 through a gate-tension 4 to a set of feed rollers 5 comprising an upper smooth steel presser roller 6 spring-loaded on to a pair of fine-fluted steel rollers 1. The material proceeds to a second set of rollers 8,comprising' an upper roller 9, which may be leather-, r'ubber-, or cork-faced, springloaded on to a steel roller I 0. A conductor ll leads the material into the nip of the rollers 9, l0.

The roller l0is driven by a chain 12 driven from a pair of elliptical gears l3, I the average peripheral speed of the roller being substantially in excess of that oftherollers I, so as to impart a draft of 10 times, or advantageously 15 timesor' upwards, to the continuous filaments. The filaments are thus successively broken into staplefiber, and at the same time the bundle 'is reduced considerably in size because of the applied draft.

The drive from the elliptical gears l3, l4 causes the draft to vary periodically, the rollers 1 not being subject to speed variation, and a corresponding periodic variation isimparted to the assasm thickness of the staple fiber product delivered to the cap-spindle l5. In this way, a close simulation to the thickness variation found in many natural staple fiber products is obtainedat a speed at least times greater than the first,

so as to break and draft at least some of the filaments, varyingthe speed of the second set at intervals during the breaking and drafting to produce varying thicknesses in the yarn simultaneously with said breaking.

2. Process for the conversion of continuous filaments into sta'ple fiber yarns and like products, comprising passing a bundle of continuous filaments through two sets of drafting rollers of,

which the first set of rollers is more heavily loaded than the second and the second is driven at a speed at least times greater than the first, so as to break and draft at least some of the filaments, varying the speed of the second set at intervals during the breaking and drafting to produce varying thicknesses in the yarn simul taneously with said breaking. I

3. Process for the conversion of continuous filaments into staple fiber yarns and like products, comprising passing a bundle of continuous filaments of an organic derivative of cellulose through two sets of drafting rollers of which the second is driven at a speed at least 5 times greater than the first, so as to break and draft at least some of the filaments, varying the speed of the second set at intervals during the breaking and drafting to produce varying thicknesses in the yarn simultaneously with said breaking.

4. Process for the conversion of continuous filaments into staple fiber yarns and like products, comprising passing a bundle of continuous filaments of an organic derivative of cellulose that have been stretched so as to have a high strength through two sets of drafting rollers of which the second is driven at a speed at -least 5 times greater than the first, so as to break and draft at least some of the filaments, varying the speed of the second set at intervals during the breaking and drafting to produce varying thioknesses in the yarn simultaneously with said breaking. I

5. Process for the conversion of continuous filaments into staple fiber yarns and like products, comprising passing a bundle of continuous filaments of cellulose acetate that have been stretched and then. saponified so as to have a high strength through two sets of drafting rollers of which the second is driven at a speed at least 5 times greater than the first, so as'to break and draft at least some of the filaments, varying the speed of the second set at intervals during "the breaking and drafting to produce varying thicknesses in i the yarn simultaneously with said breaking.

6. Process for the conversion of continuous filaments into staple fiber yarns and like products, comprising wetting a bundle of continuous filaments, and passing said filaments in a wet condition through two sets of drafting rollers of which the second is driven at a speed at least 5 times greater than the first, 'so as to break and draft at least some of the filaments, varying the speed of the second set at intervals during the breaking and drafting to produce varying thicknesses in the yarn simultaneously with said breaking. a

7. Process for .the conversion of continuous filaments into staple fiber yarns and like products, comprising passing a bundle of pigmented continuous filaments through two sets of drafting rollers. of which the first set of rollers is more heavily loaded than the second and the second is driven at a speed at least 10 times greater'than the first, so amt break and draft at least some of the filaments, varying the speed of the second set at intervals during the breaking and drafting to produce varying thicknesses in the yarn simultaneously with said breaking. 8. Process for the conversion of continuous filaments into staple fiber yarns and like products, comprising wettin a bundle of pigmented .co'ntinuous .filaments of cellulose acetate that have been stretched so. as to have a high strength and passing said .filaments in a wet condition through two sets'of drafting rollers of which the second is driven at a speed at least 5 times greater than the first, so as to break and draft at least some of the filaments, varying the speed of the second set at intervals during the breaking and draftingto produce varying thicknesses in the yarn simultaneously with saidbreaking.

9. Process for the conversion of continuous filaments into staple fiber yarns and like products, comprising wetting a bundle of pigmented conti'n ous filaments of cellulose acetate that have been stretched and then saponified so as to have a high strength, and passing said filaments in a wet condition through two sets of drafting rollers of which the second is driven at a speed at least 5 times greater than the first, so as to break and draft at least some of the filments, varying the speed of the second set at intervals during the breaking and drafting to produce varying thicknesses. in the'yarn simultaneously with said breaking.

CLAUDE HORROCKS HAYS. I WILLIAM ALEXANDER DICKIE. 

